Renewable electric fuse



Nov. 24,1925; 1,562,494

F. N. CONANT RENEWABLE ELECTRIC FUSE Original Filed June 14,A 1921 /a 36 Se 4f 2;;

,P20971 a, HAMM N W ha l Patented Nov. 24, i925.

UNITED STATES FRANKLIN N. CONANT, OF NENBURYPORT, MASSACHUSETTS.

RENEWABLE ELECTRIC FUSE.

Reled for abandoned application Serial No. 477,384, filed June 14, 1921. This application filed March 5,

t/,Z ll/mm t may concern: Be it known that I, FRANKLIN CoNAN'r, a citizen ot the United States, residing in Newburyport, in the county of Essex and State of hilassachusetts, have invented an improvement in Renewable Electric Fuses,`

This result can bo accomplished by the use of a finely divided filling material. or perishable washers, and in other ways with more or less success. is my object to accomplish this result by a structure containing a small number of large parts, durable and easily assembled without the aid oi tools, which ll believe to be better than any hitherio used. Il' is also my object to provide an apparatus which will continue to be effective notwitlistanding the usual inaccuracies in i'onunercial manufacture, and the changes duc to repeated blowings of the fuse.

.ltis also my object to combine the end closing means with means 'for preventing` rotation of the blades and an adjustable gas check in a single element.

A further object is generally to improve the construction and operation of electric fuses.

Fig. 1 is a plan view, partly broken away, of an enclosed electric fuse having knife blade 'fuse terminals and embodying my inveution.

Fig. 2 is al sectional detail along line 2--2 ol F 1.

Fig. 3 is an end view of Fig.

Fig. 4l is an end view of Fig. end cap removed.

Fig. 5 is an end view o'l' Fig. 2 with the oud cap and gas sealing means removed.

Fig. 6 is a transverse sectional view through the gals sealing means.`

Fig. 7 is a view of the inner end of the gas-scaling .means disposed on a knife-blade terminal.

2 with the Serial No. 623,029.

Fig. 8 is a view of the gas sealing means of Fig. 2, with the knife-blade locking disc removed and exposing to view the gas-sealing members.

Fig. 9 is a view similar to Fig. 7 with Jthe gas sealing members in clamping position on the knife blade.

Fie. 10 is a plan view of the gas-sealing mem ers.

Fig. 11 is an end view of Fig. 10.

As here shown the fuse embodying my invention includes the insulating tubular enclosing casing 10. A errule l1 is iixed securely on the end thereof by pins 12 in the usual manner, or by other suitable means. Said ferrule is composed of metal and has the externally screw-threaded portion 13 adapted to receive removably an interior-lythreaded end cap 111. Said :tei-rule formed with an inturned lip or end-wall 15 which extends over the end of the casing; and said end-wall is formed with the aperture V1G and a pair or' notches 1,7 extending outwardly from said aperture at diametri-V cally opposite points. Said end wall is or may be also formed with the vent passages 18 therein through which gas is or may be discharged froml the interior ofthe. casing 10 into the space between the errule and end cap after along passage between cool metal surfaces; and gas may also escape from the interior of said casing through the aperture 16 and notches 17.

The knife-blade fuse terminal 19, which is made as a blade or flat plate, has suitable means for the renewable'attachment of the fusible element, for instance, a bolt-receiving aperture in its inner end adapted to receive the bolt 2O by which the fuse link 21 is secured to said terminal; and said terminal also has the oppositely disposed notches 22, 22 in its edges which receive the endwall 15 when said blade is projected through the aperture 16 in the end wall o'll said ferrule by way of the notches 17 therein and turned a quarter of a revolution. Vith this construction the terminal is held in the casing against longitudinal movement.

The end closure consists of the cup "23 having the :Hat end Wall 24 and the outwardly flaring side Wall 25 the inner face 25a of which is adapted to form an' annular cam face as will hereinafter be described.`

lill) The Vend Wall of said cup is formed with an elongated rslot 2 6 adapted removably to receive the knife-blade fuse terminal. Two semi-circular Wedging plates or gas sealing members 27 are received. Within said cup and comprise plates formed preferably with bevelled peripheral edges 27 adapted to conform with the slope ot and enga-ge the inner cam face 25d of said cup. Said members 27 are formed with complementary recesses 28 therein arranged to receive the fuse terminal and be pressed in firm engagement therewith; and the faces 29 ot' said members are arranged to contorni vto the profile of and `snugly engage said terminal and fornranearly z(gas tight seal between the members and said terminal. Said members are formed with elongated apertures 30 adapted to receive rivets by which the elements of the gas-sealing means are retained in operative relation to each other.

A pressure disc or plate 3l is .disposed over said sealing-members. Said disc is formed with the'l struck-out, `diametrically opposed lips 32 Whichare adapted to enter the notches 17 in the end 'ferrule l1 and lock the knife blade fuse terminal against rotary movement. Said disc is also `formed with the aperture 855 adapted to .receive the fuse terminal airdinwardly entendedilips 234;, on opposite sides ot said aperture v'arranged to engage and provide increased bearing surlaee for the support of the terminal. Rivets are loosely passed through apertures in said disc and the apertures SO in said gas sealing ,members and are fixed in ...he end Wall of said clip thus making a single element of the end closing means, and the arrangement `of the cup7 sealing` inembers disc is such that all are loosely retained in position.

In assembling the fuse structure, the end closing element, the assembly ot which is illustrated in Fig. 6, is slipped over the fuse terminal when the latter is in position in the casing, and disposed yagainst the end Wall oli the ferrule ll with the lips ,32 in. .the notches l'. The end c ap ll is then screwed on the"-y lferrule and forced against the .end Wall ot the cup It the end cap cannot ybe screwed into place tread ily by reason of the tact that the `gas Sellin@ .mr-z mber s '27 do not slip together st tule bla s easily, the 'members 2.7 may be .shaken ist@ pla-@ if the tub@ is held with its vertical, but in general there is no diniculty in `serewfving lon the @ed .Cep all@ forcing the sealing members 27 tightly ,against :the terminal blades. The gas sealing members are thereby v compress ed vb etyveenl `the pressure disc 3l and .the @up feed., by reason .0f the eef-11 tw@ 2o of the cup -vvill be forced inwardly Seward each eter and the @dees thereof y ,l be brought yinto tight contact with the [lat laces oit the fuse terminal so that an expulsion of gas 'from the interior ol' the casing over the surlace el? the 'fr-.se teri'ninal Will be prevented. The curved portions 29'LL of the terminal-engaging face of said mombers are adapted to be in snug and substantially gas tight engagement with the edges of the fuse terminal and the members are arranged to be substantially in Contact beyond the fuse terminal .vhereby there will. be no ls1ibstantially expulsion of gas at these points.

lt will be noted that the as-scalinglmeans abore described also acts as a terminal clutchingmeans by which the terminal is held firm in the The end cap lil is provided with a plurality of apertures 353 in its side Wall and said apertures which term vent pas, s through which gas is expelled from the interior ofthe 'fuse casing. The outer diameter of the terrule ll, beyond the threaded portion, is necessarily somewhat less than the internal diameter of the end cap so that an annular cl'iamber 36a is formed bet' the `lierrule and end cap in which the Will expand and be cooled before it is cxpelled tliirough the vent apertures; and said apertures are preferably so disposed in toe rend cap that7 when th cal is screwed in place, they communicate with the en treme inner end ol said chamber, whereby to pro fido a lone;` path over the cooling surfaces oft the 'lierrule and end cap. This comparatively tree release oli the pas through the vents 36 cooperates with the seals 27 in preventing the hot Atrom taking the short cut along the terminals.

rlhe end closing' element above described may also be applied. as an attachment to many existing l'uses or the general character aborc set forth.

lt is obvious thrt the in\.'ention may be incorporated ln modiiied structures Without departnig Yfrom the spirit ther-colf.

I claim:

l. A renewable enclosed electric luse ot the cartridge type coinprisine the combination of a tubular enclosing casing, a lcnileblade fuse terminal extended outwardly from within the casing, plates haviim,v complemeijital terminal recesses therein adapted to conform to and envelop said. terminal, and means arrange-:il to press said 'plates inwardly toward each other and into substantial gas tight enr);` gement with said. terminal.

2. A renewable enclosed electric fuse oli' the `cartridge type comprising the combination of a tubular enclosing; casing, a knifeblade fuse terminal extended outwardly from Within the casing, and Wedging members having complemental terminal recesses therein adapted to conform to and envelop said terminal, said wedging;v members also having Wedgjng` faces, and means arranged l lsaid werljinijinzg` faces and press said wedginf members into gas tight engagement with said terminal and including` an end cap carried b r said casing and enclosing said wedginp' members.

3. il renewable enclosed electric fuse ot the cartridge type comprising Vthe combination ot a tubular enclosinf;` casing, a knifeblade 'tnse terminal extended outwardly :trom within the casing;j an end cap removably threaded on the eirl ont said casing, and means to seal the casing` against expulsion of ras around said terminal including a plurality oit eomplenientaryv wedging` members haring wedging Yl'aces arranged to be forced into engagement by said end cap, wherebyT said wcdging` members are forced into substantial gas tight engagement with said terminal.

l. fr renewable enclosed electric fuse of the cartridge type comprising the combination ot a tubular enclosing casing, a knifehlade fuse terminal extended outwardl)7 troni within the casingv` an end cap removably three ded on the end or' said casing, and. mea-ns lo seal the casing;l agrari st expulsion oit ras around said terminal includ ing` a pluralitiv ot' co1nplementai?,7 wedffjingr members harina` taces shaped to conform to the proiile ot said terminal7 and means to :torce said wedfring nien'ibers into tight engagement with said tern'iinal includimi` welding means associated with said end cap.

remnrable enclosed electric fuse ol" the cartridge type comiirising the combinan tion oit a tubular enclosing casing, a kniteblade ruse terminal extemlcd ontwardl)T trom within the casing, means to seal the casing against expulsion o't gras around said terminal inclndinry a plln'alitjif ot complementar); n'tal'ejingii members ha ving;- tacos shaped lo conform to the proile oli said terminal and also haring wedding itaces, means to engage said \.icdg finr' taces and torce said 'wedeingr members into substantial gas tight rngfjarement with said terminal and an end cap remorablji' screw-threaded on the end olz said :using arranged to act on the aforesaid il' owing-means.

renewable enclosed electric Vtuse ot the carzrirlgc tlrljie comprising the combimiv tion oi' a lubrdar eificlosing raising, a kniteblade vtuse terminid extended outwardly :from within the casingn and means to seal the casini: against expulsion oi as around said terminal including a pluralit)T of complementary wedgringr n'ieinbers having faces ,shaped to contorni to the profile of said termitral al cup lniriiii;v a cam face in which said wedding members are received and arranged to :torce said wedgin1 members into gas tight engagement with said terminal, anl an end cap enclosing said 1dredgingr members and cup and removabl5T threaded on the md of said casing.

l I i. A

7. li. renewable enclosed electric Al'fuse oit the cartridge type comprising` the combination of av tabular enclosing;- casing', a knife blade fuse terminal extended outmrardl)7 'trom Yifi'thin the casing, and means to seal the casing' against expulsion oi' gas around said termii .l incliuling` a pressure plate disposed on said terminal, a pluralityv oli' eomplenrentar)7 wedging' members disposed on said terminal in iront ot said plate, said wedging members having faces shaped to conform to the profile of said terminal, a cup having' a camatace adapted to bear against said wedding` members and torce them into gas tight engagement with said terminal,

and an end cap enclosing said wedging members and cup and removably threaded on the end o't said casino'.

8. A renewable enclosed electric fuse of' the cartridge type comprisingl the combination ol a tubular enclosing' casino', ay knife blade Afuse terminal extended outwardl)7 from within the raising, and mea-ns to seal the easing' against expulsion ot gas around said termii'ial including` a pressure plate disposed on said terminal, a plurality' o't complementari7 wetlr'in;` members disposed on said tern'iinal in front of said plate1 said weiilg'ing members l'iaifing` :taces shaped to conform to the prolile o'tI said terminal, a cup haring; a cam-tace adapted to bear against said wedfvimg members and :torce them into gas tight engiijagement with said i'm'minal7 and an end cap enclosing;l said edging members and cup and removably threaded on the end of said casingJ said end cap ha ring` rent apertures in it.

i). ,fr renewable enclosed electric inse ot the cartridge type comln'isingrthe combination ot ay tubular enclosing casing'. an ei:- teriorl \,7 threaded terrule secured on the end ot said casingr said 'tei-rule having an end wall with an aperture and a pair ot opposed notches therein, a knite blade inse terminal having' a pair ol notches in which the end `wall ot said Ytei-rule is received, a pressure plate received on said terminal having a pair or lips entered in the notches in said end wall a. pair ot complementary wedginii` plates disposed on sa id terminal .haifingl laces shaped to contorni to the profile ot said terminal, a cup havinga cam 'tace arrangeifl to engage and torre said wedgine' plates into gas tight cngagen'ient with said terminal, and an end cap removably screwA threaded on said terrule arranged to compress said cup, wedging` plates and pressure plate between it and the end. wall of said errule.

l0, A renewable enclosed. electric fuse ol the cartridge type comprising the combination of a tubular enclosing casing, an exterioilythi'eaded terrule secured on the end ot said casing', said ferrnle haring' an end wall with an aperture and a pair of opposed notches there zi lniilc hlnile of notches in which 'ieri-ille received, e pressure plate receweir on sind terminal- 'hiiving a pair o: lips entere l in the notches in. seid enti- Well, a pair oll complementary Wetlging plates flisposefl on seid terminal having; faces shzipcal to contorni to the prolile ol siii/.l terminal, :i cup lieving :i carni hice :lrrzinejeil to energie :iwi 'force seid 'weilpingi' pliitef; into lit cngi'iigement i. said terminal. rivets l y connecting seul cup :mil Weilging plates und pressure plate. zinil zin @nil czip removably screwthresilecl on siiiil "iierrule arranged to conipress said. cup and veiilg' pls. es and pressure plete between it unil the eni'l wall ot said ferrule.

ll. An attach-nient for rfi, renewable enclosed. electric fuse oli the cartridge type having a knife-blade liise terminaln which comprises a` cup having a terminal receiving; slot and an annuler cani lace, it pair oi wedging plates received in seid @up arranged peripl'ierally to the :annular im talee ol saiil cn 3, plates niring complementerj,7 recesses therein arranged suhstantiallg.T to contorni to i' prolile oi? said terminal, a.` pressure plete clisposeil nptern'iinzil having a p the enil Wall or siii on saidv Weclging plates u hevine terminal receiving slot, and nenni-.i to secure the above named. elements loosely together.

l2. An attachment for a .renewable enolosefl electric fuse of the cartridge type having e lniiie-hliicle fuse 'erniinah which comprises e cup having` n termineil-receiving slot and sin ai'innlzu. cem tace, a, p21-ir otufeflging plates received in siiiil cup iii.'- rzmgecl peripherallj7 to engage the zii'iniiliir Cain 'face of seid cup, suiiil plates having compl.ementsiij7 recesses therein errzii j substantially to eon'forin to the prolile et siiicl terminal, ai pressure plete dispose-il upon said weclging plates and having lL lierl receiving;` slot. and rivets loosely cencing the aforesaid elements.

ll. in attechnient lor zi renewable enclosed lectrio fuse ol the cartridge type having zi knife-blade ilfuse terminal, which comprises ii Cup having ai terininal-receiving slot zin/l :in annular cam hice, :i parir ot' Weclging plates receivedL in said cup zirrzingeil periplier-lli7 to engage the annular cern leee oit saifl eup, seid plates having coinplenientiirv recesses therein arranged substantially to contorni to the profile ot siiil terminal. zi pressure plate (lisposeil upon said iveflgii plates having i pair of oppositelvaiisposeil lips and i terminal receiving slot anal a priir o lips arranged to engage the terminal, und rivets loosely connecting; the aforesaid elen'ients.

lll. ln en enclosed. electric .frise of the cartridge type, the combination ot a ferrulecl insulating 'fuse casing` having,` an inturnecl lip et the end ol the errule with oppositelv-disposed notches, :intl e fusible element having zi terminal lede with notches in its for engaging seid lip by Way o? tl'e notches therein, a pressure plate for the terminal blade Which substrintiiilly closes the open enel of the casing, and. lips ittingg with the notches in the inturnefl lip ol the 'ierrule and other lips hugging the terminal iliade, ai pair o'l': Wedging plates having complementei'3fr reeesses therein zirrsngeil siibstiintially to conform to the proille of said terminal, i cu p having,` e terminal receivinv slot anil an annuler cani 'fece ur ranged to engage the peripherj7 ol sziii'l Weeping plates intl press them into engagement with sziiil terminal, und :in en l up exerting pressure on siiiil eup mul Weclv'ing plates und pressure plate :unl liolifling;` the pen-ts assembled.

ln testin'iony whereof, I have signed my naine to this speciicetion.

4FRf/tllKLIN N. CONANT. 

